Resilient cable actuated door



y 7, 9 J G. H. HUFFERD m 2,288,711

"ESILIENT CABLE ACTUATED DOOR Filed Sept. 16, 1.940 2 Sheets-Sheet l YHJ/ETZTET* E Gear eff/7 ere! fl 726107 gag/mm July 7, 1942.

G. H. HUFFERD EI'AL RESILIENT CABLE ACTUATED DOOR Filed Sept. 16, 1940 2 Sheets-Sheet 2 [my E: n ZUF 5 Patented July 7, 1942 UNITED STATE RESILIENT CABLE ACTUATED DOOR Matthew P. Graham, Detroit, Mich., assignors to Crawford Door Company, Detroit, Mich., a corporation of Michi- George H. Hufferd and g an Application September 16, 1940, Serial No. 356,998

4 Claims.

This invention relates to upward acting door constructions which are counterbalanced by a resilient cable in such a manner that equal forces are applied. to the opposite side edges of the door, thereby preventing cocking of the door in the doorway.

More specifically the invention relates to counterbalancing mechanism for upward acting garage doors of the sectional type wherein a coil spring cable provides the sole counterbalancing force.

In counterbalancing upward acting doors it is customary to apply the counterbalancing forces at the side edges of the door. Heretofore two independent counterbalancing means have been used, one on each side edge of the door. Such independent counterbalancing means, however, require frequent adjustment to exert equal forces to the opposite edges of the door. Even when perfectly adjusted, however, an initial manual lifting force near one side edge of the door to start the opening of the door will disturb the balanced forces and cook the door in the doorway thus causing it to jam in the-tracks and in some instances permanently throwing the door out of alignment.

The present invention now overcomes these difficulties and utilizes a resiliently expansible and contractable cable having its free end connected to the opposite side edges of the door and having all intermediate portions thereof movably mounted so that equal balancing forces will always be applied to both side edges of the door. In accordance with this invention, a helically coiled spring is secured at its ends to the side edges of the door adjacent the bottom of the door. The cable is then trained over sheaves mounted on horizontal shafts at the top of the doorway so that the cable can extend rearwardly from tqmary overhead tracks. Sheaves mounted on vertical shafts are provided at the inner ends *of the tracks and. receive the cable therearound so that the cable can bridge the space between the horizontal overhead tracks. This provides 5 a floating mounting for all intermediate portions of the spring cable and equal forces must therefore always be applied to the opposite side edges of the door. a

If desired the spring cable can be made in two lengths but these lengths are connected together to operate as a single unit.

It is, then, an object of this invention to provide a counterbalancing mechanismfor upward acting doors which automatically applies equal the doorway to the inner ends of the cus- 40 counterbalancing forces to opposite side edges of the door.

A further object of the invention is to eliminate cocking of an upward acting door in a doorway.

A specific object of the invention is to provide a resilient cable means for counterbalancing an upward acting door and in so mounting the cable means to exert equal forces at different portions of the door.

Another specific object of the invention is to provide an upward acting door construction of the sectional type with a helically coiled spring counterbalancing mechanism floatingly mounted between two spaced portions of the bottom door section.

Other and further objects of the invention will be apparent to those skilled in the art from the following detailed description of the annexed sheets of drawings which, by way of example. disclose apreferred embodiment of the inven- 'tion.

On the drawings:

Figure 1 is a broken elevational view of a doorway viewed from the inside thereof and having a sectional type upward acting door mounted therein counterbalanced by a resilient cable mechanism according to this invention.

Figure 2 is a vertical cross-sectional view of the doorway taken along the line 11-11 of Figure 1 and illustrating parts in end elevation.

Figure 3 is a broken vertical cross-sectional view taken along the line III--III of Figure 2.

Figure 4 is a fragmentary plan view illustrating the manner in which the coil spring cables of the counterbalancing mechanism can be tightened.

Figure 5 is an isometric view illustrating the floating mounting for the counterbalancing cable mechanism.

Figure 6 is an enlarged horizontal cross-sectionail view taken along the line VI-VI of Figure Figure 7 is a vertical cross-sectional view taken along the line VII-VII of Figure 6.

Figure 8 is a horizontal cross-sectional view taken along the line VIII--VIII of Figure 2.

Figure 9 is a top plan view along the line IX--IX of Figure 3.

Figure 10 is an end elevational view along the line X-X of Figure 9.

As shown on the drawings:

In Figures 1 and 2 the reference numeral l0 designates generally a door adapted to close a doorway defined by side door jambs 12, a

lintel I3 and a floor M. A ceiling l5 extends inwardly from the lintel I3.

Vertical tracks I6 are mounted by means of angle strips II to the inner faces of the door face of the lintel l3 above the top of the door opening ll support the curved track portions 20.

As best shown in Figures 6 and 8, weatherstrips 22 are secured to the opposed doorway defining faces of the jambs l2 and to the lintel I3. These weatherstrips extend inwardly from the jambs and lintel to provide, with their inner edges 22a, an abutment for the door l0.

As 'best shown in Figure 1, the door It is built up from a bottom panel or section Inc, an intermediate panel or section lb, and a top panel or section I00. The sections are articulately connected by means of hinges 23 secured to the inner faces of the adjoining panels at the side edges of the door and supporting laterally projecting rollers 24 which ride in the tracks.

Angle brackets 25 are secured to the inner face of the door section |0a at the bottom corners thereof and, as shown in Figures 6 and 7, have legs 26 extending over the side edges of the door and rotatably supporting additional rollers 21 riding in the tracks. In accordance with this invention the side legs 26 have extensions 26a projecting forwardly and outwardly into the spaces S defined by the inner faces of the door jambs l2, the weatherstrips 22, angle strips l1 and the tracks l6, for a purpose to be hereinafter described.

The top side edges of the door panel |0c carry brackets 21 secured to the inner face of the panel and supporting laterally projecting rollers 23 which ride in the tracks.

The door I0 is thus composed of articulately connected panels or sections which are guided on rollers carried by vertical and horizontal tracks to slidably mount the door for movement from a closed vertical position to an open horizontal overhead position.

In accordance with this invention the brackets 2| carry horizontal stub mafia-.30 on which are rotatably mounted sheaves 3|. The sheaves 3| are disposed directly over the spaces S described above and shown in Figures 6 and 8.

The inner ends of the horizontal tracks I8 have flat horizontal plates 32 secured to the tops thereof and extending toward each other beyond the top flanges |8a of the tracks as best shown in Figures 3 and 9. These plates 32 carry vertical stub shafts 33 on which are rotatably mounted sheaves 34. The sheaves have grooved peripheries extending over the longitudinal center of the track flanges l8a.

A v-shaped trough member 35, which can be an ordinary angle iron strip, is bifurcated at the ends thereof by cutting off portions of its bottom at the ends of the strip to provide open ended recesses 36. The furcations are then flattened out to provide fingers 31 as best shown in Figures 9 and 10. The flattened fingers are mounted on the plates 32 with one finger of each pair under a sheave 34. The member 35 bridges the horizontal tracks l8 at the inner ends thereof.

An elongated helical coil spring 38 is secured at one end 38a thereof to the finger portion 26a of the bracket 25 at the right side edge of the door and extends from this finger through the space S over the right-hand sheave 3| and thence rearwardly over the right-hand horizontal track I8 around the right-hand sheave 34 toward the other sheave 34 above the trough member 35. A second elongated helical coil spring 39 has an end 39a thereof secured to the finger 26a of the lefthand bracket 25 and extends upwardly through the leit-hand space S around the sheave 3|, thence rearwardly above the left-hand track I8 and around the sheave 34 above the trough member 35 toward the other coil spring 38. The other ends 38b and 39b of the coil springs are connected by means of a wire hook 40.

The wire 40 is also disposed above the trough 35 and integrally joins the two springs 38 and 39 into a unit. Obviously,'of course, a single coil spring could be used in place of the two spring lengths. However, as illustrated in Figure 4, the use of two springs 38 and 39, connected by means of a hook 40, makes possible a tightening of the spring tension by merely hooking the wire into coils of the spring spaced from the ends 38b and 39b thereof.

The coil spring unit is, of course, resiliently contractable and expansible and is anchored only to spaced portions of the bottom panel Illa at the side edges of the panel. All other portions of the spring unit are floatably carried around readily rotatable sheaves.

The spring unit must, therefore, exert equal forces on the opposite side edges of the door, and these forces are automatically balanced even when the door is given a manual lifting thrust from one side edge thereof.

The spring unit acts both as a counterbalance and as a cable threaded over the horizontal tracks and adjacent the vertical tracks.

The trough member 35 acts as a support for the rear run of the spring unit and prevents a downward looping of the spring when the door is in open position.

The sheaves 3| are mounted directly above the fingers 26a of the bottom bracket 25 so that the vertical runs of the spring unit will effect a straight upward pull. Likewise, the sheaves 34 are aligned with the sheaves 3| to guide the rearward run of the spring unit directly over the horizontal tracks I8. Therefore, no binding action will occur between the spring cable and the sheaves.

The vertical runs of the spring cable will pull the door In upwardly in the vertical tracks l6 while the superimposed door panels will articulate relative to each other and be transferred to the horizontal tracks Ill.

The coil springs used, in this invention, both as spring actuators and cables, need not be very heavy to fully counterbalance even a quite heavy door, because the springs are very long and added length is obtained by threading the springs from the front to the rear ends of the horizontal tracks. Coil springs from one-half to one inch in diameter are quite ample to provide any necessary counterbalancing force. Since the springs are quite long, each coil is only very slightly flexed and the springs will have exceptionally long wearing life.

The spaces S provided for the vertical runs of the springs will efilciently prevent accidental physical contact with the springs by persons op- 4 erating the door. Even the overhead runs of the springs are provided with supports Thus even though a spring cable should give way when in stretched condition, it cannot possibly cause injury to any person in the garage or building.

It will, of course, be understood that various details of construction may be varied through a 1 wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

We claim as our invention:

1. A counterbalancing mechanism for upward acting doors adapted to move from closed vertical position in adoorway to horizontal overhead open position in tracks extending inwardly from the doorway which comprises an elongated resiliently expansible and contractable cable unit having the ends thereof connected to opposite side edge portions of the door, a pair of freely rotatable sheaves mounted at the top of the doorway, a second pair of freely rotatable guide sheaves mounted above the tracks at the inner end portions of the tracks, and said cable unit trained intermediate its ends around said sheaves to extend upwardly along the side edges of the door over the first pair of sheaves thence rearwardly in direct overlying relation to the tracks around the second pair of sheaves and thence acrossthe space between the inner ends of the tracks. I

'2. In an upward acting door construction of the sectional type including a door having a pluond pair of rotatable guide sheaves mounted above the horizontal tracks portions at points remote from the vertical track portions, each of said cables being trained around the sheaves to extend directly above the horizontal track portions and extending toward each other between rality of liingedly connected superimposed panels, tracks at each side edge of the door having communicating vertical and horizontal'portions;

and rollers mounted on said door extending into said tracks, the improvements which comprise a pair-of elongated coiled spring cables each secured to an opposite side edge portion oi the bottom door panel, a pair of rotatable guide sheaves mounted above the vertical track portions. am-

the horizontal track portions, and means connecting the extending end portions of the cables tocause the same to act as a unit, said means beingadjustably connected with said cables to load the same. I

3. In an upward acting .door construction including vertical and horizontal tracks at each side edge of the door for supporting the door for movement from a closed vertical position to an open overhead horizontal position, the improvements which comprise rotatable sheaves above the vertical tracks in alignment with each horizontal track, additional rotatable sheaves at the ends of the horizontal tracks remote from the vertical tracks, an elongated spring cable trained around said sheaves and bridging the space between the horizontal tracks at the remote ends of the tracks, brackets anchoring the ends of said cable to opposite side edges of the door, and a track-bracing trough member bridging said horizontal tracks and fixedly connected thereto to underlie the cable for receiving the cable therein when the spring is unloaded. 4. In an upward acting door construction includinghorlzontal overhead tracks extending inwardly from-a doorway, the improvement which comprises a track-bracing channel strip having flattened ends mounted on top of said tracks and defining an open topped trough bridging the tracks, and a spring counterbalancing means movably mounted above said trough and adapted to be supported in the trough.

GEORGE H. HUFFERD. MA'I'I'HEW P. GRAHAM. 

